Glue pen



FIG. 1 is a side elevational view of a glue pen showing my new design;

FIG. 2 is an front plan view of the glue pen as shown in FIG. 1; and,

FIG. 3 is a rear plan view of the glue pen as shown in FIG. 1. 

I claim the ornamental design for a glue pen, as shown. 